Just  quick post to document a troublesome error when running Jmeter on Mysql

JDBC Request: Cannot load JDBC driver class’com.mysql.jdbc.Driver’ solution

Should be pretty simple, it’s just a question of putting the mysql-connector-java jar file, available at https://dev.mysql.com/downloads/connector/j/, into the classpath for Jmeter. The easiest way for me is to put this into the jmx file:

      <stringProp name=“TestPlan.user_define_classpath”> /Users/kyle.hailey/jars/mysql-connector-java-8.0.29.jar,/home/ec2-user/jars/mysql-connector-java-8.0.29.jar</stringProp>

Notice there is a space ” ” before the first jar file.  Apparently the space  was enough to cause the error. After removing the space , jmeter connected successfully to …

I recently wanted to check all tables’ current AUTO_INCREMENT value (if any) for a database dump structure. I wasn’t sure if a tables’ Data Definition Language (DDL) statement contained the current AUTO_INCREMENT value or not. So after I loaded the dump file, I learned of a query to use and find out…

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The following is a short HOWTO about deployment and use of Benchmark-kit (BMK-kit). The main idea of this kit is to simplify your life in running various MySQL benchmark workloads with less blood and minimal potential errors.

Generally as simple as the following :

$ bash /BMK/sb_exec/sb11-Prepare_50M_8tab-InnoDB.sh 32   # prepare data

$ for users in 1 2 4 8 16 32 64 128 256 512 1024 2048
do   
  # run OLTP_RW for 5min each load level..
  bash /BMK/sb_exec/sb11-OLTP_RW_50M_8tab-uniform-ps-trx.sh $users 300
  sleep 15
done

the latest public online version of the following HOWTO is always available from here : http://dimitrik.free.fr/blog/posts/mysql-perf-bmk-kit.html

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High availability and replication is a must for any production environment in order to have a back-up process in place with minimum interruption in case of failure. In this article, I'll explain how to configure this architecture for MySQL HeatWave on OCI.

I could barely stuff this week’s OpenLampTech issue #31 into the email client to send out. It is that full!

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In this week’s OpenLampTech issue #31, we are covering articles on:

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Full table scans can be problematic for performance. Certainly if the scanned tables are large. The worst case is when full table scans are involved in joins and particularly when the scanned table is not the first one (this was dramatic before MySQL 8.0 as Block Nested Loop was used) !

A full table scans means that MySQL was not able to use an index (no index or no filters using it).

Effects

When Full Table Scans happen (depending of the size of course), a lot of data gets pulled into the Buffer Pool and maybe other important data from the working set is pulled out. Most of the time that new data in the Buffer Pool might even not be required by the application, what a waste of resources !

You then understand that another side effect of Full Table Scans is the increase of I/O operations.

The most noticeable symptoms of Full Table Scans are:

• increase of CPU usage
• increase of …

Who dares diagram a system and process as complex as InnoDB page flushing? I do.

Who dares diagram a system and process as complex as InnoDB page flushing? I do.

Who dares diagram a system and process as complex as InnoDB page flushing? I do.